1. Field of the Invention
The present invention relates to a circuit arrangement for telecommunications systems, particularly telephone exchange systems, comprising a respective central information-processing system and a central switching matrix network, and comprising sub-switching matrix networks identically connected thereto, subscriber lines and/or trunks connected to the sub-switching matrix network. Further, a respective partially-centralized switching system is individually assigned to the subscriber lines and/or trunks for the acceptance of information, for example line signals, selection identifiers, line characters and the like, incoming over the lines, for processing the signals, as well as for transmitting control signals over the lines, for example alternating current call pulses, audio signals, selection identifiers and line characters, and over which the connections setup over the central switching matrix network are through-connected both for an incoming line to the central switching matrix network and outgoing to a line with respect to the direction of call setup. The information acceptance operation and/or information transmission operations executed in the context of these two through-connection operations required per connection lay claim to the respective partially-centralized switch system at least once per through-connection event. The partially-centralized switch device forwards the information unaltered or preprocessed to the central information processing system respectively assigned in common to the switch devices and has a limited call-handling capability with respect to its information processing capacity. A device is provided for identifying the information processing traffic load and for recognizing and averting information processing traffic overloads.
2. Description of the Prior Art
A circuit arrangement of this general type may be derived from the systems description "EWSD Digitales Elektronisches Wahlsystem, Systembeschreibung A30808-X2589-X-1-18"of Siemens AG. With respect to questions of averting traffic overloads, it was presented in a lecture at the "9th INTERNATIONAL TELETRAFFIC CONGRESS (ITC)" in October 1979 in Torremolinos, Spain (Conference paper ITC-9 of SOMOZA et al, pp. 1-7), that, given a system having a central computer and partially-centralized switching devices, the formation of overload signals occurs in the central computer. Proceeding beyond this, the German application No. P 32 36 130 discloses that overload signals formed in a central information-processing system are transmitted to partially-centralized switching devices in order to accomplish an overload defense in the switching devices, whereby this known instance also proceeds on the basis that an information flow from each of the partially-centralized switching devices to the central information-processing system occurs. It is therefore expedient, for this reason, that the measures for averting overloads already occur in the partially-centralized switching devices.